Radiocircuits



May 2 1, 1930.

G. S. CORNISH RADIOCIRCUITS 2 Sheets-Sheet l Il l l E 4. l E E T L 1 (,I/QV/X. m wm ou. h un .G on N www .n

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oBNEv May 27, 1930. G. s. mmm-4 1,759,991V` RADIOGIRCUITS Filed oct. 4, 1924 2 sheets-sheet 2 H mam' Y y liiatented provided theusual filament and' plate; 'but in'- Which more ,than v` one grid vrelexnervit@.is Y asso;

ciatedtherewith. `1-

is to roduce a yfcircuitfin Wbiclithefu'sefo Y a tubek 'aving more-thanfonegrid elenielityvill bring'about results such as them'receptionqo-k. radio signals with. less static and .local interference yand at the vsaine' `tiinefwithf a: greatei'1 Y degree of strength` and clarity than has loerevljy tutore been possible. 'without' va 'corresponding increase inthe strength offsuch; objectionable interference .as is .usually experienced-:- l

l ,Afurthurobject'i to producea radio cir-7';

cuitgin which tubel oscillation lpreVented,y :from occurring at timesv most criticaltof the Y f proper receptionofthevpadio'signal, WithoutA v,20, n n

, Zing capatiegfalldi Silpllllrliry expediente* ytendedfor such pur-p9Se@A c having tol resort to such Vdeyicfes" as 'neutral-- A' .further object'is .tov K'cir-v Cuit in which they principlesfsuggested 1n the A:oregoing objects are readily, applicable to radiIO Vfrequency :amplification fand to detection gwhen tubes .shaving more ,than fone y 'grid' 'are-employed- J f These and,otlierJobjectsareattained in the invention` `set `forth .in the yfollowing specili'y cation and illustratedtinjthe. accompanying drawing,inwliichz"' tovtli'e radio frequency stages*only,v tbetubes n -lFe'liS'adl gramma, .'circuitconsistingfofitwo stagesv ofradio fre-` quency Vamplification 'and al detector, themic yieyy of a radio Vention herein haVin-gbeen shown als applied for ,suoliy purposes Ahaving `4been shown fas fof A' the type @nobodyhis .wrath/an 011e srild- .llr f ".Figef, isa diagrammaticyiew of'a detectory circuit employingfthejprinciple of theiny'eni l tion; hereink set fvforth, tliej detector tube f this purpose being offtheftypeeniploylng "'more than1onefgrid.f w Y Fig. 3 is a diagrammaticwvieyv ofrua .one

rstage"-'audio amplification circuit suitable forf Vaddition topthecf Circu i "j 31H12. r

` Fig. f 4f isl a diagrammatic View-of a' radio y circuit consisting of two stagesfpo'f"sradi'fre .e

y "Application l1-19d" oetoii'er 4,. 1924. 1 serial Na7/1371. g e, lnections tl1'ere'oi'. f Q

c l f ,p ifi v A, but'sliowinga furtherinodication. l f Angobject of theinyention hereindescribed,y

l the.' Ydesired signaLisprevented t is Well' knowntliat capacity coupling"between'.the'` vdesirable:particularly in amplifierf ciruits,r` Y yinasmuchV as ,theyv completely disguise *fthe` r l signal/'Which it is desiredto amplify. InjfA order toxovercoinetlie objections to yvhic'li' I1 y been'to eniployspecial condensers or'the pu .ary vcoilsxof the radio frequency transformers quency'aniplication andl as f Fig. l, but showing a' lI'nodilication ofthecon-,ffV ing.. 51S ayviwquite sminaatogiigs; iand fg, e f VThe1ere?en?e 01? earafaty @welliesretireer#y tWox..electriei c1rcu1ts,-as'f0r exainplel'the pril a Y mary; and y,secondary circuits cfa-.radio re.-

Ceyerfas exemplified inthe-radio2 frequency l primary-and,secondarytransformer{coilsfon G0 i thejradiolrequency ainplilication endo'i the usual receiyenresults in thetransinissionof j undesirable signal disturbances. '-SelectivityfV of, thelreceiyer is destroyed and reception ofy gridlandplate circuits .of *audion orv radio ,lf tuberfrequentl results in the'productionof oscillations.A uch. oscillations areyeryfun have referred, onevyfo the usualfmethQ'dS j pose of neutralizing the'fintereleinent capa ity .0f 31301111111. tubes' 0r audolle :TSlilife Y' L densers have a low capacity which,i's'gajoprfcf)z ri-`r e f j mately equal to tbe internal cap acity,V of, the tube. ,This relative equality defeats anyftend'- Q ency for a large aniountoffradio frequency current to pass back through the tube to the grid,` but is neutralized by the combinationv of f i 'the neutralizing jcon'densers, the'interel'elnent 1 capacityoftlie-tubes and the secondary y'vind-l ,85 j

ings ofthe radio .frequency transformer. y nfthe'inventionpherein described intereleff v `nient"capacity of the .tubes is o'yercoine''and f I capacity coupling of tlie primary andsecondi` is eliminated tbein'ew and noyel 'manner"setl d forth yeinployorvtlnspurpose radiotubes Aofthe construction embodying morethanonej l grid. In tlie'ernbodinient of my*invention"asl j disclosed in Figs. l and 2, I llave employefdffe fourelenientor tWo grid tubesin tliefradio f ,e frequency and detector circuits; flnfFi'glflfl l fr have shownulthe radio rfeq'uien'cy".anfl'pljificlar-j` and .5,thedetaterharinabee She rtion', with. respectv to: eompaniori-gridsy I k14 and"22,'much as' is accomplished in vthev operation of neutrodynel typev receivers.

This point of connectionhappens to be shown as ata point in thesecondary'oflessi-induc tance thanthat of the (secondary connections the effettui'preventingv the tube fromloscillat-Y l' ticularly ,adaptedto Vthe reception ofi signalsof relatively 'short Wavelength. lIi-onpthe other hand, the variable` connecton'with the secondary be made With a continuation therel c. of outside thetuned or{main`portion acrossV j t kWhichthe variable condensersare placed, as shown'inFig, the yeffect will be ytof/partien ularly adaiptfthe circuittofthereception of signals of relativelylong Wave1engtl1'., i jf f' ,Furtherchangesin'connectionmaybemade by causing each extra gridto Voperate independently ofl the other@ by .connecting'it gtof vthey desired point of the secondary of the transformer to which itsfcompanion grid is yconnected as have suggested by dotted lines A' distinctness andfreedomfro'm:disturbance inj connection with 27 i1pild`ig.r 5,` instead of j 'connectingtheextragridsfinftandem. This 'f lideais also suggested .inVtheJshowing of the Vtwo grid,detectorcircuitgdisclosedin Fig. 2.

The particular feectfinfithelcase'of fthe devtectoritube isito clearupthe signalsso that theyvmay bereceived withfmateriallyggreater i than i heretofore; y' in'addition to rendring x I claim:

' them cap able of reception with consiglierably greater volume.

'differenti-inductive-Vresultsfrom those lPro#k "i d 'l duced at the pointfof connection of the first ,mentioned grid elements,v one ofsaidaudions t which are so connected being adaptedfor use f kas' a detector of Wave' signals delivered to it bythe 0thers, by having, one of its duplicateff grid elements arrangedto cause saidaudion tol function asI a detecten In testimony ,whereof I. have k,hereunto af- CoRNrsii. Y. i

loo Y y1f, Arwave signalfrespon'sive sistng of alternately fassociatediradio fref said transformers consisting' of primary kand yque'ncy transformersandaudionsg reachfof ,c

ysecondeu'y coils inductivelyrcoupledrelatively to each other, each of said-(audions possessing' 1 duplicate grid elementso`ne of sadgridjele-f ments having circuit:connection'withgone of Y saiel coils,the other ofjsaidg'rd elementsfha'v; f f ing circuit connectionv with' the same co1] as to Whichthe first mentioned grid elements are connected', but at a vpoint thereindiiery .A

ent rfrom yand adapted to producediiferent j inductive results from tliosefproduced at the 'grid elements.

circuit connection Withthe same 'coilsl as to I 'i which they first mentioned of themduplicate gridelements are' connected, butata point :therein different from' and adaptedto produce 

